1. Field of the Invention
This invention relates to an image processing system with color discrimination, and, in particular, to an image processing system capable of handling the color information of an image to be processed.
2. Description of the Prior Art
In the case of inputting image information into an image processing system, such as a facsimile machine, it is often convenient if the color information of the image to be input can be identified. For example, it is often the case that an original document to be transmitted by facsimile contains not only messages black in color, but also messages red in color, red stamps and red underlines. In such a case, if such red image information can be transmitted separately from black image information and these black and red image information can be output separately, the transmission of image information can be carried out more effectively.
Various methods for discriminating different colors of an original image have been proposed, and one of such conventional methods is to use one filter for one color in carrying out color separation. However, for example, if a red filter is used to carry out color separation so as to identify the red color, a color containing a red color component beyond a certain level, such as magenta, may be identified as a red color. For this reason, there is a disadvantage in that some colors other than those which are visually discriminated as a red color are often identified as a red color. In addition, in the case where a red color image signal is formed from an input signal containing only a red component in this manner, the light-receiving level becomes relatively low, so that there may be a case where a red image signal cannot be output properly depending on the kind of red color.